Portable press

ABSTRACT

An inexpensive portable pneumatic press which is intended primarily for compressing mechanical or electric connecting elements of electric conductors, cables and the like, in which a ram is driven by one or two cylinder-and-piston units extending transverse to the ram by means of at least one pair of toggle arms which are moved with an equal force toward each other. When the ram approaches its final compressing position, the toggle arm acts upon a control member which shifts the control valve to its venting position.

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mted States Patent [151 Hoeckele May 9, 1972 PORTABLE PRES 3,398,5678/1968 Olsson ..29/203 DT 72 l nt Max Hoeckel St h, G 1 emac manyFOREIGN PATENTS OR APPLICATIONS {73 1 Ass'gnee Karl. l Fabnkelektmtechmscl" 289,506 7 1953 Switzerland ..29/200 Spezmlarttkel,Stuttgart-UnterturkheIm, 427 944 7/1967 Switzerland 79/200 Germany [22]Filed: Primar i- E.\'aminer-Thomas H. Eager [211 App. No: 16,462Atlorney-Arthur O. Klein 57 ABSTRA T [30] Foreign Application PriorityData 1 C An inexpensive portable pneumatic press which is intended Feb.18, 1970 Germany ..P l9 12 908.9 primarily for Compressing mechanical orelectric connecting elements of electric conductors, cables and thelike, in which a U.S. ram i driven one or two cylinder.and piston unitsextend. [5 lnt. transverse to the'ram means of at least one pair of tog.Field of Search 13,203 203 gle arms which are moved with an equal forcetoward each 29/200 B other. When the ram approaches its finalcompressing position, the toggle arm acts upon a control member whichshifts [56] References Cited the control valve to its venting position.

UNITED STATES PATENTS 13 Claims, 3 Drawing Figures 3,329,002 7/1967Schwalm ..29/203 DT i 5 4/ E0 2/ 9 6 /9 /7'/6 40 I7 PATENTEDMAY 91972.3,660,883

SHEET 1 OF 3 In ventor:

Max HOE 5M by: I tOII'IBV PATENTEDHAY 91972 V 3,660,883

SHEET 2 0F 3 Inventor Max HOEfKEL E by: M

Attornev FA'TE'NTEMY 91972 V 3,660,883

arm 3 0F 3 Inventor:

Max HOECKELE by: M4 AH ornev PORTABLE PRESS The present inventionrelates to a portable press, especially for compressing mechanical orelectrical connecting elements of electric conductors, which comprises aram which is movable toward a fixed abutment by means of a pair of armswhich are pivotably connected at one end to the ram and at the other endto a cylinder-and-piston unit which is operated by compressed air so asto drive the ram.

In portable presses which should be capable of compressing connectingelements of conductors of small as well of large cross-sectional sizesit has always been a problem to provide suitable means for producing thedifferent high pressures which are required for properly compressing thedifferent connecting elements. In manually operated presses in which theforce which the operator exerts upon a hand lever is transmitted to theram by means of a bell crank, toggle lever or an eccentric, thecompressive forces which may thus be produced are relatively smallunless an additional transmission or a very long hand lever is provided.Such an additional transmission or such a long hand lever renders,however, the manipulation of such a press unnecessarily difficult ifonly small compressive forces are to be exerted. While such presseswhichare driven hydraulically easily permit very high pressures to beproduced, the pumping movement which has to be carried out by means of ahand'lever or the like requires, however, an excessive length of time ifonly small pressures have to be exerted upon small connecting elementssince the ram of the press has to be moved in all cases along the entiredistance which is necessary to close the tool. In order to overcome thisand other disadvantages of a hydraulic drive of such a press, it hasbeen proposed to employ a cylinder-and-piston unit in which the pistonis driven by conducting gases into the pres sure chamber of the cylinderwhich are produced by the explosion of a cartridge. However, theseexplosion drives also have a series of disadvantages, chiefly among themthe fact that the deformation of the connecting element occurs toosuddenly and that the ratio between the power and distance of travel ofthe piston is very unfavorable inasmuch as the force of the piston whichis produced by the expansion of the explosion gases diminishes thefarther the piston has to travel. It is therefore necessary to employcartridges with different propellant charges in accordance with thedifferent cross-sectional sizes of the connecting elements which are tobe compressed. This involves the danger that a cartridge of an improperstrength might be employed and that the connecting element may either bemashed or insufficiently compressed. Finally, there have also beenpresses of this type which were operated by compressed air by means ofcylinder-and-piston units. These known pneumatic presses were, however,of an expensive construction and also very uneconomical because theyrequired very large amounts of compressed air.

It is an object of the present invention to provide a portable press ofthe type as described at the beginning which is operated pneumatically,is of a simple and inexpensive construction, may be easily manipulatedto compress connecting elements and the like of differentcross-sectional sizes, and is capable of producing high pressures and ofbeing operated very economically. According to the invention, thisobject is attained by moving the ram of the press by means of at leastone pair of arms which are pivotably connected at one end to the ram andat the other end to two connecting elements which are movable inopposite directions to each other and transverse to the direction ofmovement of the ram. At least one of these'connecting elements is formedby a piston rod of a pneumatically operated cylinder-and-piston unit.Further features of the invention for attaining the above-mentionedobject consist in the provision of a throttle member in thecompressed-air line leading to the cylinder of this unit, in

providing a control valve which by the manual actuation of a trigger ismovable from a position in which it vents the compressed-air lineleading from this valve to the cylinder to the operating position inwhich it connects the supply line of the compressed air to the cylinderso that the piston in this cylinder will be driven and the ram willcarry out a compressing stroke, and in further providing the movablemember of this control valve with a control member which, when thetrigger is actuated, projects into the path of travel of the mentionedconnecting elements so that, when the piston arrives at a point near theend of its driving stroke, these connecting elements will engage uponthis control member and thereby shift the valve member to its ventingposition so that the ram and piston may then be retracted by at leastone return spring.

Due to the provision of the togglelike connecting arms intermediate thepiston rod and the ram, the ration between the distance of travel andthe force exerted by the ram is very favorable since at first the ramcarries out very quickly a relatively long part of its stroke and nearthe end of its entire stroke exerts an increased pressure. It istherefore possible by means of a relatively small cylinder-and-pistonunit and a pressure as supplied by a conventional source of compressedair to produce the required ram pressure for compressing connecting orother elements of large cross-sectional sizes. A very important featureof the invention also consists in the provision of the throttle memberwhich retards the build-up of pressure in the pressure chamber of thecylinder of the pneumatic unit. This prevents the compressionv of theconnecting or other elements from being carried out too quickly and italso reduces the required amount of compressed air to a minimum sincethe movement of the piston is carried out in accordance with thepressure which the ram has to exert, and therefore only such a pressurehas to be produced in the cylinder as is actually required. A furtherincrease in pressure in the cylinder and thus an unnecessary consumptionof compressed air is avoided according to the invention by the provisionof the control member which automatically interrupts the supply ofcompressed air when the ram reaches its final compressive position. Inorder to carry out a compressing operation, the operator therefore needsto do no more than to actuate the trigger. This fact and the low weightof the entire press which is due to its simple construction permit thepress to be very easily manipulated.

According to one preferred embodiment of the invention, the press needsto be provided only with a single cylinder-andpiston unit. While in thisembodiment, one of the two connecting elements is, of course, pivotablyconnected to the piston rod, the other connecting element is pivotablyconnected to the cylinder. This is insofar of advantage as the forceswhich are exerted by the connecting elements upon the two arms willnecessarily be of exactly the same strength and no force of reactionwill occur which may have to be taken up by a housing or othersupporting elements of the press. Since in this case not only the pistonbut also the cylinder carries out a movement, provision has to be madeto permit the air supply line leading to the cylinder not to interferewith this movement of the cylinder. Although this supply line could, ofcourse, consist of a flexible tube, it has been found to be of advantageto make it of two sections which are telescopically slidable within eachother but are tightly sealed relative to each other and extend parallelto the longitudinal axis of the cylinderand-piston unit.

According to another preferred embodiment of the invention, the press isprovided with two cylinder-and-piston units which are preferably coaxialand the pistons of which are movable in opposite directions to eachother, while their cylinders are rigidly connected to each other. Thetwo connecting elements may in this case consist of the two piston rods.

Regardless of whether the press is equipped with a singlecylinder-and-piston unit or with two of such units, it is of advantageto connect one end of at least one further arm pivotally to eachconnecting element in a position coaxially to the pivot axis of the armwhich connects this element to the ram and to connect the other end ofthis further arm pivotably to a tool supporting head in which the ram isslidable and which also carries the fixed tool and takes up directly theforce of reaction of the ram.

The throttle member may be of a very simple type which consists of athreaded pin which is loosely inserted with play into a tapped bore. Ithas been found to operate very reliably.

The control valve may consist of a slide valve which is provided withconnecting bores and is axially slidable in a connecting block, whilethe control member for returning this slide valve to a position in whichit shuts ofi the compressed air supply line and vents the cylinder maysimply consist of one or a pair of projections which, when the valvemember is moved by the trigger to its operative position, projects intothe path of travel of the connecting elements or the anns thereon and isengaged by the latter at the ends of their movement toward each otherwhen the ram reaches its full compressive position and is then depressedby a cam action so as to move the valve member to its venting position.

The features and advantages of the present invention will become moreclearly apparent from the following detailed description thereof whichis to be read with reference to the accompanying drawings, in which FIG.1 shows a longitudinal section of the portable press according to afirst embodiment of the invention;

FlG. 2 shows a cross section which is taken along the line ll ll of FIG1; while FIG. 3 shows a longitudinal section of the press according to asecond embodiment of the invention.

As illustrated particularly in FIG. 1 of the drawings, the portablepress according to the invention which is to be employed, for example,for compressing clamps, connecting terminals, connecting sleeves and thelike comprises a substantially C-shaped head 1 which has two arms whichare provided with coaxial bores 2 and 3 which extend parallel to theyoke of this head 1. Bore 2 is adapted to receive the mounting pin ofafixed tool 4 of an associated pair of tools, while the other tool 4'rests on one end surface of a ram 5 and is held in this position by itsmounting pin which is inserted into an axial bore of the ram 5. Ram 5 isaxially slidable within and guided by the wall of bore 3 and surroundedby a coil spring 6 which engages with an initial pressure at one endupon the head 1 and at the other end upon the enlarged base 5' of ram 5.Due to this enlarged base 5, ram 5 is substantially T-shaped.

This base 5' of ram 5 is provided with two parallel bores which extendsymmetrically to the longitudinal axis of ram 5 and at right angles tothe direction of movement of the ram and contain two hinge pins 7 whichare locked in a fixed position by screws 8. Two pairs of equal arms 9are pivotably mounted at one end on each of these pins 7, while theother ends of one pair of these arms 9 are pivotably connected by a pin10 extending parallel to the pins 7 to one end ofa connecting rod 11which extends transverse to the longitudinal axis of ram 5. The otherend of this connecting rod 11 forms a flange 11' of a larger diameter,and this flange and the connecting rod 11 are provided with a centralsocket bore 12 the bottom of which is located near the pin 10. The wallof this bore 12 is provided with two diametrically opposite longitudinalslots 13 at the sides facing the arms. 9.

The other end of the second pair of arms 9 is pivotably connected by apin 14 to a piston rod 15 the enlarged head of which is guided by thewall of the central bore 12, while pin 14 projects through thelongitudinal slots 13 of rod 11. Flange 11 is screwed into the open endof a cylinder 17 of a cylinderand-piston unit 16. Piston rod 15 isconnected to a piston 18 which is slidable within the cylinder 17 andcarries a coil spring 40 which surrounds the piston rod 15 and ispressed against flange 11' when during its driving stroke piston 18 hastraveled for a certain distance from the bottom 17 of the cylinder,

Two equal pairs of arms 19 are further pivotably connected at one end topins 10 and 14, respectively, and at the other end to a pair of pins 20and 21 which extend parallel to pins 10 and 14 through the arm of head 1in which the bore 3 is provided and are equally spaced from this bore 3.Spring rings 41 or the like on the ends of pins 10, 14, 20 and 21prevent these pins from sliding out of the bores into which they areinserted.

At the side of the connecting rod 11 opposite to ram 5 a connectingblock 23 is mounted in a fixed position in a housing 22. This connectingblock is provided in axial alignment with ram 5 with a bore in which aslide-valve member 24 is slidable which has a U-shaped control member 25secured to its end facing the ram 5. As may be seen in FIG. 2 the twoparallel arms of this control member 25 are spaced from each other at adistance which is substantially equal to the distance between the twoarms 9 and, as shown in FIG. 1, the free ends of these arms of themember 25 are rounded. The other end of valve member 24 which likewiseprojects from the connecting block 23 engages upon one end of a trigger26, which is pivotably mounted in the housing 22, and the other end ofwhich projects from this housing so as to be easily manipulated. Whenthis end of trigger 26 is depressed, valve member 24 will be shiftedagainst the action of a return spring in the direction toward the ram 5.

At the side of the connecting block 23 facing the cylinderand-pistonunit 16 this block 23 carries a guide tube 28 which extends parallel tothe longitudinal axis of cylinder 17 and the bore 27 of which isconnected with the bore in which the valve member 24 is slidable andalso contains one end of a connecting tube 29 which is axially slidablein this bore 27, while the other end of tube 29 is inserted into thebottom 17' of cylinder 17 and communicates through a connecting bore inthe bottom 17 with the cylinder chamber. An annular gasket 30 preventsthe compressed air from passing between the outer wall of tube 29 andthe inner wall of guide tube 28 to the outside. The slight movement ofthe cylinder-and-piston unit 16 transverse to its longitudinal axiswhich may occur during the pressing operation of the apparatus leads toa slight bending of the connecting tube 29 which is, however, so elasticthat the tight sealing action of gasket 30 will not be impaired.

The wall of the bore in block 23 in which valve member 24 is slidable isprovided at a certain distance in the axial direction of this bore fromthe point where bore 27 terminates into it with a second bore 31 intothe outer threaded end 32 of which a setscrew 33 is loosely inserted andforms a throttle member. This threaded bore 32 is connected between therear end of the head of setscrew 33 and a screw 34 which closes theouter end of bore 32 to another bore which leads to a connecting line 35which may be connected to a source of compressed air, not shown.

Valve member 24 has a central bore 36 which is closed at both ends, andtwo transverse bores 37 and 38 which are spaced from each other at adistance equal to the distance between the two connecting bores 27 and31.

When the apparatus is in its released position as shown in FIG. 1, bore37 of valve member 24 is in axial alignment with the connecting bore 27,while bore 38 is located outside of the connecting block 31 so that thepressure chamber of cylinder 17 is vented via tube 29 and the mentionedbores. In the operative position of valve member 24, however, bore 38 isin alignment with the other connecting bore 31. When valve member 24 isin this position, the two arms of the control member 25 also projectinto the path of movement of the lower ends of the arms 9.

The mode of operation of this press is as follows:

When one pressing operation has been completed, all movable parts of thepress are automatically shifted to the position as illustrated inFIG. 1. For effecting the next pressing operation, trigger 26 isdepressed and valve member 24 is thereby shifted to its operativeposition in the direction toward the ram 5. Compressed air may then flowthrough the connecting line 35, the throttle 33, the valve bores 31, 36and 37 and the bore 27 and then through the connecting tube 29 to thepressure chamber of cylinder 17 so that the piston 18 will be movedtoward the flange 11' and pins 10 and 14 will thereby be moved with anequal force toward each other. Since due to the throttle 33 the pressurewill be built up slowly in the pressure chamber of cylinder 17, thispressure will at any time only have the strength as required by theparticular position of ram 5. As soon as ram 5 reaches its end position,the ends of arms 9 which are pivotably connected to pins and 14 alsoreach a position in which they push the control member 25 which islocated between them by a cam action so far in the direction toward theconnecting block 23 that a further supply of compressed air will bestopped and valve member 24 will be returned to the venting position asshown in FIG. 1. The compressed air can therefore escape from thepressure chamber of cylinder 17 and pass to the outside. Suitable means,not shown, may be provided to reduce the noise of the escapingcompressed air. Ram 5, arms 9, piston 18 and arms 19 will then bereturned to their original positions as shown in FIG. 1 at first by theaction of both springs 6 and 40 and then only by the action of spring 6.The connecting tube 29 is then also pushed back to its original positionin guide tube 28 from which it was pulled out during the pressingoperation for a distance in accordance with the shifting movement of thecylinder. Since spring 40 will be compressed only during a part of thestroke of piston 18, the amount of compressed air required for thepressing operation will be reduced.

The second embodiment of the invention as illustrated in FIG. 3 differsfrom the first embodiment as shown in FIGS. 1 and 2 merely by theprovision of two cylinderand-piston units l16-and 116. These two unitsare of identical construction and extend coaxially to each other, andtheir pistons 118 and 118 which are disposed at opposite sides of thehousing 122 operate in opposite directions to each other. The connectingmember 111 which again extends transverse to the direction of movementof ram 105 is provided on each end with a flange 111' which is screwedinto the associated cylinder and thus connects both cylinders to eachother. The pair of arms 109 which correspond to the arms 9 in FIGS. 1and 2 which are connected to the base of the ram 105 are in this caseconnected to the piston rod 115, 115' of the cylinder-and-piston unit116, 116. A further difference between this embodiment of the inventionand that according to FIGS. 1 and 2 consists in the provision of anadditional connecting tube 123' which leads from the connecting block123 to the pressure chamber of the cylinder of the cylinder-and-pistonunit 116'. Furthermore, the connecting tubes 129 and 129 are rigidlyconnected to the connecting block 123 and do not need to betelescopically slidable relative to this block since the two cylindersare not movable relative to the housing 122.

In order to prevent the trigger of the press as shown in FIG. 3 frombeing depressed accidentally when the press is not to be operatedimmediately, the part of this trigger which projects from the housing122 is completely covered by a safety cap 140 which is connected to thehousing so as to be pivotable about an axis 141, while a spring 142tends to maintain this cap 140 in its closed position. In order to beable to actuate the trigger, the operator of the press must thereforefirst pivot the safety cap 140 in the clockwise direction, as seen inFIG. 3, which he may do with one finger of the same hand holding thehousing 122 or with his other hand. Although this safety cap may be ofany other suitable construction, it is shown in FIG. 3 as consisting ofan inner part 140{ of sheet metal which is covered by an outer layer140" of plastic.

Apart from the differences as previously described, the press asillustrated in FIG. 3 is of the same construction as the press as shownin FIGS. 1 and 2. Of course, the last-mentioned feature of providing asafety cap for the trigger may also be applied to the press according toFIGS. 1 and 2 to cover the trigger 26.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, 1 wish to have it understood thatit is in no way limited to the details of such embodiments but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

l. A portable pneumatic press for compressing electrical connectingelements of electrical conductors, cables, and the like, comprising atool support having an abutment, a ram axially slidable in said toolsupport relative to said abutment, at

v least one cylinder-and-piston unit having a piston rod, a pair ofconnecting elements movable in opposite directions to each other andtransverse to the direction of movement of said ram, at least one ofsaid connecting elements being rigidly secured to said pistonrod, atleast one pair of driving arms pivotably connected at one end to saidconnecting elements and at the other end to said rarn, an air supplyline for conducting compressed air to the cylinder of said unit, athrottle member in said supply line, a control valve in said supplyline, a control member connected to said valve and having one endadapted to project into the path of travel of said connecting elementsand to be acted upon by the latter when said rarn reaches its fullcompressing position so as to move said valve member to its ventingposition, and a manually actuated trigger for shifting said valve memberfrom said venting position to a position in which it connects saidsupply line to said cylinder.

2. A portable press as defined in claim 1, in which one of saidconnecting elements is secured to said piston rod and the secondconnecting element is secured to said cylinder.

3. A portable press as defined in claim 2, in which said secondconnecting element forms a rod having a central bore, said firstconnecting element being slidable within and guided by the wall of saidbore, said wall having a pair of longitudinal slots diametricallyopposite to each other, and pivot pins connecting said connectingelements to said driving arms, at least one of said pivot pinsprojecting through and slidable along said slots.

4. A portable press as defined in claim 1, in which said air supply lineleading to said cylinder has a part extending parallel to thelongitudinal axis of said unit, said part being divided into twosections which are telescopically slidable relative to each other, andmeans for sealing said two sections relative to each other.

5. A portable press as defined in claim 1, in which two of saidcylinder-and-piston units are provided, the pistons of said two unitsbeing movable in opposite directions to each other and the two cylindersof said units being secured to each other, said two connecting elementsbeing secured to the piston rods of the associated pistons.

6. A portable press as defined in claim 5, in which said two cylindersare secured to each other by a rod having a central bore, the pistonrods of said two pistons being slidable within said bore and guided bythe wall thereof, said wall having a pair of longitudinal slotsdiametrically opposite to each other and terminating into bothcylinders, and pivot pins connecting said connecting elements to saiddriving arms and projecting through and slidable along said slots.

7. A portable press as defined in claim 3, further comprising at leastone pair of second arms also pivotably connected at one end to saidpivot pins and at the other endto said tool support.

8. A portable press as defined in claim 1, further comprising springmeans for returning said ram and the piston of said unit after eachdriving stroke.

9. A portable press as defined in claim 1, in which said throttle memberconsists of a threaded pin loosely inserted with play into a tappedbore. v

10. A portable press as defined in claim 1, in which said control valvecomprises a connecting block and a slide valve member slidable in saidconnecting block and having connecting bores.

11. A portable press as defined in claim 10, in which said valve memberextends coaxially to said ram and is slidable in the longitudinaldirection of the latter and located at the side facing the side of saidram to which said driving arms are connected, said control member beingadapted to project from said valve member into the path of travel ofsaid driving arms.

12. A portable press as defined in claim 11, in which the end of saidvalve member opposite to that carrying said control member engages uponsaid trigger, and spring means tending to maintain said valve member ina retracted position and in engagement with said trigger.

13. A portable press as defined in claim 1, further comprising a housingcovering at least some of the elements of said press and having anaperture, said trigger pivotably mounted on said housing and partlyprojecting through said aperture to the outside, a cap adapted to coverthe outwardly projecting part of said trigger, and a spring normallytending to maintain said cap in said covering position.

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2. A portable press as defined in claim 1, in which one of saidconnecting elements is secured to said piston rod and the secondconnecting element is secured to said cylinder.
 3. A portable press asdefined in claim 2, in which said second connecting element forms a rodhaving a central bore, said first connecting element being slidablewithin and guided by the wall of said bore, said wAll having a pair oflongitudinal slots diametrically opposite to each other, and pivot pinsconnecting said connecting elements to said driving arms, at least oneof said pivot pins projecting through and slidable along said slots. 4.A portable press as defined in claim 1, in which said air supply lineleading to said cylinder has a part extending parallel to thelongitudinal axis of said unit, said part being divided into twosections which are telescopically slidable relative to each other, andmeans for sealing said two sections relative to each other.
 5. Aportable press as defined in claim 1, in which two of saidcylinder-and-piston units are provided, the pistons of said two unitsbeing movable in opposite directions to each other and the two cylindersof said units being secured to each other, said two connecting elementsbeing secured to the piston rods of the associated pistons.
 6. Aportable press as defined in claim 5, in which said two cylinders aresecured to each other by a rod having a central bore, the piston rods ofsaid two pistons being slidable within said bore and guided by the wallthereof, said wall having a pair of longitudinal slots diametricallyopposite to each other and terminating into both cylinders, and pivotpins connecting said connecting elements to said driving arms andprojecting through and slidable along said slots.
 7. A portable press asdefined in claim 3, further comprising at least one pair of second armsalso pivotably connected at one end to said pivot pins and at the otherend to said tool support.
 8. A portable press as defined in claim 1,further comprising spring means for returning said ram and the piston ofsaid unit after each driving stroke.
 9. A portable press as defined inclaim 1, in which said throttle member consists of a threaded pinloosely inserted with play into a tapped bore.
 10. A portable press asdefined in claim 1, in which said control valve comprises a connectingblock and a slide valve member slidable in said connecting block andhaving connecting bores.
 11. A portable press as defined in claim 10, inwhich said valve member extends coaxially to said ram and is slidable inthe longitudinal direction of the latter and located at the side facingthe side of said ram to which said driving arms are connected, saidcontrol member being adapted to project from said valve member into thepath of travel of said driving arms.
 12. A portable press as defined inclaim 11, in which the end of said valve member opposite to thatcarrying said control member engages upon said trigger, and spring meanstending to maintain said valve member in a retracted position and inengagement with said trigger.
 13. A portable press as defined in claim1, further comprising a housing covering at least some of the elementsof said press and having an aperture, said trigger pivotably mounted onsaid housing and partly projecting through said aperture to the outside,a cap adapted to cover the outwardly projecting part of said trigger,and a spring normally tending to maintain said cap in said coveringposition.